Efectos de los biocidas en la resistencia a los antibióticos

5. Does biocide use contribute to the development of antibiotic resistant bacteria?

There have been several laboratory studies that show a
possible link between exposure to
biocides and antibioticresistance. However, other
investigations have not found such a link.

Exposure to biocides can
affect bacterial
populations so that only the
resistant strains survive,
and this has been associated with increasing
resistance to
antibiotics. This could be
relevant for biocides used in consumer goods because a small
number of biocides are used widely in many different household
and personal hygiene products. As a result, the
bacteria on human skin and
in homes are repeatedly exposed to certain
antimicrobial products.
However, it is not clear whether this type of bacterial exposure
to biocides will lead to
antibiotic
resistance.

Data are scarce but there is some evidence of a link between
using biocides in
veterinary products, and increased
resistance to
antibiotics. This
emphasizes the need to develop research and surveillance
programmes in the area of animal husbandry.

Measuring the effect of
biocides on the way that
bacteria react to
antibiotics is far from
straightforward. In experiments, a group of bacteria are first
treated with a biocide and those that survive are then tested to
see to what extent they are affected by antibiotics. This latter
stage is complicated and the results are often hard to interpret
because several mechanisms may modulate
antibiotic susceptibility.
Recent data clearly demonstrate that some biocides activate
genetic controls that are involved in triggering
resistance mechanisms that
alter both biocide and antibiotic activity.

Some studies on bacteria
that grow as biofilms have
investigated whether using
biocides can lead to the
emergence of more
resistant strains, and the
results vary depending on the
species of bacteria and on
the biocide used. Some studies showed that biocide use had no
effect on the development of
resistance. Other studies
found that using biocides made some strains of bacteria grow at
the expense of others, and that successful bacteria were less
easily affected by biocides.
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